Different types of automatic assembly machines are known for mounting semiconductor chips onto a substrate. At one end of the spectrum one finds the so-called Die Bonders that are used in order to mount semiconductor chips onto a substrate at high speed and with great accuracy. Such Die Bonders are known for example from the patent U.S. Pat. No. 6,185,815, and the patent publications EP 991 110, US 2005-0011067 and US 2004-0246794. The semiconductor chips are presented on a wafer table. The substrates to be equipped are supplied one after the other in cycles whereby one substrate at a time is fixed to a substrate table and presented for equipping with semiconductor chips. Mounting of the semiconductor chips is done by means of a bondhead driven by a pick and place device. Die Bonders marketed by the applicant contain a pick and place device with a first fast axis that enables the transport of the semiconductor chips from the wafer table to the substrate at high speed and with a second axis running orthogonally to the first axis that allows shifting of the semiconductor chip in the range of several tens of micrometers so that any deviation of the actual position from the set position can be corrected. This concept enables a simple and favourable method of construction however limits the Die Bonder to the effect that each time only one specific semiconductor chip can be mounted onto the substrate. At the other end of the spectrum one finds so-called automatic placement machines that have two fast axes running orthogonally to each other that cover a large working area. The advantage of this concept is that several different types of semiconductors as well as other components can be mounted one after the other onto the same substrate. The disadvantage is that the assembly time is much greater than with a Die Bonder.
With the Die Bonder, the substrates are pushed forward in cycles by a transport device and, with substrates having several substrate places lying next to each other in columns, are processed column by column. The substrate is only pushed forward when a column is fully equipped with semiconductor chips. There are also applications with which several columns are combined into a block. Because the forward feed with the transport device during equipping of a block for various reasons is often undesired, Die Bonders have been developed with which the substrate table can be shifted in transport direction together with the substrate fixed to the substrate table so that the columns of a block can be equipped without having to release the fixing of the substrate to the substrate table.
From U.S. Pat. No. 6,519,840 a semiconductor mounting apparatus is known with which the position of the semiconductor chip presented on the wafer table is measured by a camera before it is picked and a correction of any positional deviation of the semiconductor chip from its set position is done in that the foil is held by the die ejector by means of vacuum and then at least the upper surface of the die ejector facing towards the foil is shifted in the plane running parallel to the underside of the foil. The movement range of this die ejector is comparatively small, as it only has to enable small correction movements.
From U.S. Pat. No. 6,149,047 a semiconductor mounting apparatus is known with which the wafer table, the pick and place device and the die ejector can be moved in two horizontal directions so that the semiconductor mounting apparatus has room in the smallest possible space despite the increasing size of the wafers. The disadvantage is the distinct slowing down of the assembly process.